You are the project manager for software development project. The feasibility study can start any time and takes 1 week and requirement gathering takes 2 weeks which can start only after feasibility study. The design and test plan development can start in parallel after the requirements gathering. Test plan preparation takes 8 weeks followed by a review by the customer and the time estimated for review is 1 week. After the review, Test data preparation takes 6 weeks. Design takes 6 weeks and it is followed by development and unit testing, for one module it takes 2 weeks and for the other module it takes 2 weeks. There are no dependencies between modules and they can be developed simultaneously. After test data preparation and development and unit testing of both the modules, there is 2 weeks system testing. What is duration of the critical path ？（）
A．14 weeks
B．15 weeks
C．20 weeks
D．19 weeks
参考答案：C
解析：
你是软件开发项目的项目经理。可行性研究可在任何时间开始，需要花费1周；需求收集必须在可行性研究完成之后进行，需要花费2周。设汁和测试计划开发可以在需求收集后并列进行。测试计划准备需要花费8周，接下来是客户评估，客户评估预计花费1周。评估之后，测试数据准备需要花费6周。设计花费6周，接着是开发和单元测试，其中一个模块花费2周，另一个模块花费2周。模块之间没有依赖关系，可以同时开发。测试数据准备和开发和单元测试之后，有2周的系统测试。项目关键路径的历时是多少
A) 14周。 B) 15周。 C) 20周。 D) 19周。
关键路径为：可行性研究 测试计划开发 客户评估—设计—开发和单元测试系统测试。历时为：1+8+1+6+2+2=20周。